Chemical methods for the characterization of proteolysis in cheese during ripening

Proteolysis is the principal and most complex biochemical event which occurs during the maturation of most cheese varieties. Proteolysis has been the subject of much study and a range of analytical techniques has been developed to assess its extent and nature. Methods for assessing proteolysis can be classified under two broad headings: non-specific and specific techniques, both of which are reviewed. Non-specific techniques include the quantitation of nitrogen soluble in various extractants or precipitants and the liberation of reactive groups. Specific techniques include those which resolve individual peptides or free amino acids, principally chromatography or electrophoresis. Techniques are often combined into a fractionation scheme for cheese nilrogen to facilitate the isolation of individual peptides. Methods for the identification of individual peptides are also reviewed. Strategies for assessing proteolysis in various cheese varieties are discussed.